The present invention relates in general to a touch screen input system. More particularly, the invention relates to a novel technique for detecting the location of an object and in particular, a pointer or possibly the human finger as associated with a display device such as a cathode ray tube (CRT).
It is highly desirable to be able to automatically locate the pointer reference on a CRT for a man-machine interface. There are various existing techniques described for carrying this out. These techniques include special forms of tablets, many of which employ resistive or capacitive forms of sensing. The various techniques that are described in the literature use technology that is quite cumbersome. Furthermore, the systems are subject to wear and generally have resolution limitations.
Accordingly, it is an object of the present invention to provide an approved touch screen input system which provides an extremely simple form of interface with the display and any associated computer.
Another object of the present invention is to provide an improved touch screen input system which employs a minimum number of components and yet provides good detection resolution.
Still a further object of the present invention is to provide an improved touch screen input system that is not subject to deterioration with normal use.
Still another object of the present invention is to provide a touch screen input system in which there is no requirement for any special purpose pen or pointer. In accordance with the invention, even a standard graphite pencil may be used as a pointer.